the aion 921 vco is a variable waveform generator which produces frequencies ranging from sub-audio (lfo) to 40.000 hz. four waveforms are available: sine, triangular, sawtooth and rectangular (with variable
duty cycle a.k.a. pulse width modulation). both fixed and variable levels can be obtained from the front panel output jacks. nominal frequency and range controls (octave) are found at the top of the module.
voltage controlled rectangular width (vc-pwm) is set by the knob in the upper center (left) with the accompanying voltage input jacks. multiple frequency control inputs 1 and 2 can be plugged into this module in
parallel. control input 3 is used via the pot for linear frequency response (liniar fm). all waveform outputs can be used if desired. this is what we consider an improved version of the moog™ 921 vco, not a
direct clone. improvements were made concerning tuning and stability issues.